Study on the effects of agrinine on immunoglobulin E-induced oxidative stress in human monocyte cell line U937

• Main Authors: Yun-Shan Li, 李芸姍
• Other Authors: Kee-Lung Chang
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/91607848525443918857

碩士 === 高雄醫學大學 === 生物化學研究所 === 99 === Immunoglobulin E ( IgE ) participates in the most common instant allergic disease, hypersensitivity I, which is characterized by the increase of vascular permeability in early phase and induction of local inflammation within several minutes after allergens exposure. Release of reactive oxygen species ( ROS ) by inflammatory cells is the cause of airway inflammation. In addition, it was also found that mitochondria dysfunction in the activated inflammatory cells. L-arginine, an amino acid, has been reported to regulate immune cells’ functions and cell cycle progress. Up to now, It is still not known whether L-arginine can regulate the IgE-stimulated hypersensitivity or not. Therefore, this study was designed to explore the effects of arginie on the IgE-stimulated human monocyte cell line U937. Firstly, the trypan blue exclusion method was used to analyze the effect of arginine and/or IgE on cell proliferation; results showed after 24h treatment, 300 μM arginine and 500 ng/ml IgE could increase U937 cell proliferation. Moreover, flow cytometry analysis indicated the percentage of S and G2/M phase of cell cycle were enhanced in these proliferated cells. Treatment with IgE for 12h, increase of ROS, reduction in antioxidants - glutathione levels and mitochondrial membrane potential ( △Ψm ) were found in U937 cells. However, these changes could be prevented as combined-treatment with arginine. Conclusively, arginine treatment could inhibit the IgE-stimulated oxidative damage to U937 cells by increase antioxidants and regulation of mitochondrial function.